// 伪类嵌套 &
.clearfix {

  &:before,
  &:after {
    content: "";
    display: table;
  }

  &:after {
    clear: both;
    overflow: hidden;
  }
}

// 添加后缀  .accordion__copy  .accordion--open
.accordion {
  max-width: 600px;
  margin: 4rem auto;
  width: 90%;
  font-family: "Raleway", sans-serif;
  background: #f4f4f4;

  &__copy {
    display: none;
    padding: 1rem 1.5rem 2rem 1.5rem;
    color: gray;
    line-height: 1.6;
    font-size: 14px;
    font-weight: 500;

    &--open {
      display: block;
    }
  }
}